Question

Animal cells maintain a concentration gradient of certain charged particles across their plasma membranes. The cell pictured below experiences a gradient of positively charged Na+ ions, positively charged K+ ions, and negatively charged particles collectively referred to as Anions. Describe why these gradients exist and how it leads to membrane potential.

Answer 1

Animal cells maintain a concentration gradient of ions across their cell membranes, creating a membrane potential. This potential is the result of the active transport of ions, leading to negative charge inside the cell and positive charge outside, leading to the voltage known as membrane potential.

Step-by-step explanation:

Concentration gradients of charged particles like Na+ and K+ ions across the plasma membranes of animal cells are critical for maintaining the membrane potential. These gradients exist because there is active transport of ions that creates a difference in ion concentrations across the membrane. Gradually, cells build up a high concentration of potassium (K+) ions inside and a high concentration of sodium (Na+) ions outside.

Since the interior of animal cells contains negatively charged proteins that do not move across the membrane, the inside of the cell becomes negatively charged compared to the outside, creating an electrical gradient. Together, the concentration gradient and the electrical gradient form an electrochemical gradient, which is essential for processes such as nerve impulse transmission. The balance of these forces results in a voltage across the membrane, known as the membrane potential, which is crucial for cell function, particularly in neurons and muscle cells.